Disk drives are a type of information storage device that store information on at least one spinning disk. Other types of information storage devices include, for example, magnetic tape drives which retrieve stored information on magnetic tape (e.g. linear tape drive, helical scan tape drive). There are several types of disk drives. Magnetic hard disk drives typically store information on non-removable rigid magnetic disks. There are also optical disk drives, which typically retrieve information stored on removable optical disk media. Also for example, there are magneto-optical disk drives, which share some of the characteristics of optical disk drives and magnetic hard disk drives.
All types of disk drives typically include a spindle motor that supports and spins at least one disk media. Although past disk drive spindle motors utilized ball bearings, ball bearings have been replaced by fluid bearings in many contemporary disk drive spindle motors, for example to reduce non-repeatable runout, vibration, and/or acoustic noise.
A disk drive that is installed in a mobile device such as a laptop computer is often subjected to angular displacements during operation, which can cause the spindle fluid bearing to be subjected to gyration-induced torques. Such gyration-induced torques can undesirably increase the operation noise of the disk drive spindle, and can also accelerate surface wear within the fluid bearing.
Therefore, there is a need in the art for an improved fluid bearing for a disk drive spindle motor that is more robust to gyration-induced torques, while still providing acceptable bearing pressure and stiffness to meet contemporary specifications, and that can be practically mass-manufactured at acceptably low cost.